摘要:
An event tap associated with a server, such as a Web server, at a machine can transform a server event into a tuple, select a database node for the tuple, and place the tuple in a queue for that database node, and then flush the queue periodically directly into database notes. The use of an event tap can thus reduce the computational burden on the database while keeping the server event data in the database relatively fresh.
摘要:
The present invention addresses the problem of partitioning database relations across a plurality of hosts in a shared-nothing cluster while minimizing communication costs. A new partitioning approach for database relations—join-partitioning—is introduced that focuses on relations and their dependencies to a priori partition the plurality of relations to the plurality of hosts such that each host can locally compute a large class of queries over its partitioned data in isolation at query time, independent of other hosts in the cluster. Such an approach thus overcomes the primary bottleneck, i.e., the network, in deploying database systems over shared-nothing clusters by allowing them to seamlessly scale linearly to tens of thousands of hosts and manage tens or hundreds of terabytes of data.
摘要:
An event tap associated with a server, such as a Web server, at a machine can transform a server event into a tuple, select a database node for the tuple, and place the tuple in a queue for that database node, and then flush the queue periodically directly into database nodes. The use of an event tap can thus reduce the computational burden on the database while keeping the server event data in the database relatively fresh.
摘要:
A system and method for using failure casting to manage failures in computer system. In accordance with an embodiment, the system uses a failure casting hierarchy to cast failures of one type into failures of another type. In doing this, the system allows incidents, problems, or failures to be cast into a (typically smaller) set of failures, which the system knows how to handle. In accordance with a particular embodiment, failures can be cast into a category that is considered reboot-curable. If a failure is reboot-curable then rebooting the system will likely cure the problem. Examples include hardware failures, and reboot-specific methods that can be applied to disk failures and to failures within clusters of databases. The system can even be used to handle failures that were hitherto unforeseen—failures can be cast into known failures based on the failure symptoms, rather than any underlying cause.
摘要:
A system and method for using failure casting to manage failures in a computer system. In accordance with an embodiment, the system uses a failure casting hierarchy to cast failures of one type into failures of another type. In doing this, the system allows incidents, problems, or failures to be cast into a (typically smaller) set of failures, which the system knows how to handle. In accordance with a particular embodiment, failures can be cast into a category that is considered reboot-curable. If a failure is reboot-curable then rebooting the system will likely cure the problem. Examples include hardware failures, and reboot-specific methods that can be applied to disk failures and to failures within clusters of databases. The system can even be used to handle failures that were hitherto unforeseen—failures can be cast into known failures based on the failure symptoms, rather than any underlying cause.
摘要:
The present invention addresses the problem of partitioning database relations across a plurality of hosts in a shared-nothing cluster while minimizing communication costs. A new partitioning approach for database relations—join-partitioning—is introduced that focuses on relations and their dependencies to a priori partition the plurality of relations to the plurality of hosts such that each host can locally compute a large class of queries over its partitioned data in isolation at query time, independent of other hosts in the cluster. Such an approach thus overcomes the primary bottleneck, i.e., the network, in deploying database systems over shared-nothing clusters by allowing them to seamlessly scale linearly to tens of thousands of hosts and manage tens or hundreds of terabytes of data. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.
摘要:
In one embodiment, a method includes concurrently executing a set of multiple queries, through a processor, to improve a resource usage within a data warehouse system. The method also includes permitting a group of users of the data warehouse system to simultaneously run a set of queries. In addition, the method includes applying a high-concurrency query operator to continuously optimize a large number of concurrent queries for a set of highly concurrent dynamic workloads.
摘要:
A determination is made regarding whether to merge two symbolic analysis states. A first state corresponds to a first path through a program to a program location and a second state corresponds to a second path through the program to the program location. A set of variables of the program at the program location is determined. For each variable in the set: a) a first value of the variable in the first state is determined; b) a second value of the variable in the second state is determined; and c) a determination is made, based on the first and second values, regarding whether merging the first and second states would be advantageous. A determination is made, responsive to determining that merging the first state and the second state would not be advantageous for at least one variable in the set, not to merge the first state and the second state.
摘要:
An execution of a target software program that causes a particular bug to manifest itself is generated. A target software program is received. A bug report generated by an execution of the target software program is received. The bug report describes a particular bug within the target software program. A bug type of the particular bug is received. A synthesized execution file is generated based on the target software program, the bug report, and the bug type. The synthesized execution file specifies an execution of the target software program that causes the particular bug to manifest itself.
摘要:
A symbolic execution task is dynamically divided among multiple computing nodes. Each of the multiple computing nodes explores a different portion of a same symbolic execution tree independently of other computing nodes. Workload status updates are received from the multiple computing nodes. A workload status update includes a length of a job queue of a computing node. A list of the multiple computing nodes ordered based on the computing nodes' job queue lengths is generated. A determination is made regarding whether a first computing node in the list is underloaded. A determination is made regarding whether a last computing node in the list is overloaded. Responsive to the first computing node being underloaded and the last computing node being overloaded, a job transfer request is generated that instructs the last computing node to transfer a set of one or more jobs to the first computing node.